Razor cartridges and the non-handled portion of disposable razors (hereinafter referred to generically as razor heads) generally consist of a blade support surface with a guard bar extending from its leading edge, either a single blade or a pair of blades which may be separated by a spacer element and a cap. The blades, in one method of assembly, have either orifices or slots and are positioned over pins extending upward from the top of the blade support portion or downward from the cap. If the stakes or pins depend downward from the cap they extend through the blade support portion and are anchored in the bottom of the support portion. U.S. Pat. No. 4,205,437 issued to Evan N. Chen and Bryan J. Goddard depicts such an assembly. U.S. Pat. No. 4,535,537 issued to Frank A. Ferraro and David S. Byrne discloses a system whereby the staking means are positioned in the blade support surface and extend upward through the bottom of the cap to engage the surface on the top portion of the cap. In both of these instances, the component parts of the blade head are locked in place by applying a force to the bottom of the pin to deform the bottom and spread it out into a rivet-like configuration having a wider diameter than that of the adjacent part of the pin. The cold riveting operation can bend, deform or at times even crack the pin. This is particularly more likely if the force is delivered to the point of the pin and is not applied equally across the bottom profile.
U.S. Pat. No. 4,443,939 issued to Vincent C. Motta and Ernest F. Kiraly discloses staking with a "pop bead" approach. In this instance a stake having an inwardly tapering diameter as it extends downward terminates in a solid spheroid. The orifices positions in the receiving portion of the blade support surface, have a chamfered area around the orifice. Because of the reduced thickness in the chamfered area, the orifice, which is smaller in diameter tha the spheroid at the end of the stake, can be pushed through the orifice by deflecting the chamfered area downward. In theory, the chamfered area then springs back and positions itself around the area of tapering reduced thickness immediately preceding the sphere. This spheroid takes the place of the staking rivet and eliminates the stresses put on the pin by the riveting operation. Unfortunately, in a number of cases, the chamfered area is deflected downward but, after passage of the enlarged spheroid, does not spring back, but remains in the downwardly deflected configuration. This bending widens the hole and eliminates the secure locking fit required for razor head assembly.